Alkylation



Patented Get. 29, 1946 ALKYLATION Alexander Sachanen and Arlie A. QKelly, 'Woodbury, N. .L, and ClaudeG. M32615, Bryn; Mawr, Pa assignors to 'Soriony-Vaouum Oil Gompany, Incorporated, a corporation of New York No Drawing.

Application September 15, 1944:,

Serial No. 554,342.

This invention relates generally, to the alkylation of paraffinic hydrocarbons with olefinic hydrocarbons, and is more particularly concerned with the production of higheoctane motor fuel by the catalytic alkylationof paraffinic hydrocarbons with olefinic hydrocarbons,

It is well known in the art to polymerize ole-finic hydrocarbon gases to produce motor fuels having constituents of an unsaturated character. Various commercial processes have been proposed for ultimately effecting the desired polymerization of the olefinic hydrocarbons. These processes have been predicated upon the dictates of the chemical nature of the stocks available, as well as engineering considerations such as initial and operation costs; their essential feature being that in the course of treating the materials, the olefinic hydrocarbons produced in the earlier stages ofthe process, are eventually polymerized into, hydrocarbons boiling within the gasoline boiling range. Accordingly, hydrocarbon gases maybe passed along with cracking stock or naphtha through a cracking still, to crack and 20 Claims. (Cl. 260-.-683.4)

polymerize such gases to gasoline simultaneously" with the cracking or reforming, or paraflinic hydrocarbonv gases may be separately cracked into olef nic hydrocarbon gases and these gases are subsequently passed with naphtha through a polymerizingand reforming still. In some instances, the processes involvethe use of catalysts for facilitating the cracking and/or polymerization operations.

It is also well known in the art; to combine paraffinic hydrocarbons directly with olefinic hydrocarbons byprocesses broadly called alkylation processes, to produce motor fuels'having con stituents of saturated: character. In alkylation processes, a charge; comprising a miXture oPa paraflinic hydrocarbon, called the parafiinic' reactant, and an; olef nic hydrocarboncalled the olefinic' reactant, is subjected to high-temperature and pressure toproduce a saturated alkylate product. Since conditions of alkylation also cause polymerization of the olefinic reactant, it isnecessary to maintain a relatively lowconcentration of the olefinicreactant in the charge.

The only limit to the pressureused appears to be the feasibility of maintaining high pressures.

On the other handg'the temperature used is'limited by degradation of the hydrocarbon reactants in the charge to low molecular weight hydrocarhens, and the occurrence of side reactions, in-

eluding polymerization of the olefinic reactant,

under high temperature conditions, that substantially reduce the purity of the product obtained.

The temperatures and to a certain extent, the

pressures employed in alkylation operations, depend upon whether the alkylation is effected in the absence or presence of alkylation catalysts. The two methods are generally referred to as thermal and; catalytic alkylation, respectively. As is well known in the art, thermal alkylation ordinarily involves the use of temperatures of at least about 909 F. and pressures of the order of 4000; pounds per square inch or higher. At these temperatures, the degradation of the hydrocarbon reactants in the, charge, and; the occurrenee of side reactions, including polymerization of the olefinic reactanthis somewhat marked. On the other hand, catalytic alkylation involves the use o pp ab we emp at res, thereby ass re ing a high yield ofv desired alkylate by avoid ng extensive degradation of the reactants, the ocrrence o gs cqn a y rea9 n$, and p r ciab pol m rization of, h efirii ea nt- ,SevBr l metho s r nown o the ata y a k a ion. oi is nar n s y c ns w h q efmip,hydrocarb ns- F r stance i s. qwn to ky ate. sorarafiinic dr arb n t l finic hydrocarbons in the presence of sulfuric a id; n sp ori id, meta pho p tes m a hafidc activat d cl y d th i e as at ly t In. these catalytic alkylation processes, the hydrocarbon reactants form with the alkylation, catalysts, a heterogeneous system, during the alkylation operation. Hence these alkylation catalysts may be termed heterogeneous alkylation catalysts. Since under alkylation, conditions, the catalytic activity of the alkylation catalysts appears to be predicated upon contact between the catalysts and the gaseous hydrocarbon reactants at the interfaces therebetween, in these processes, the catalysts are, usedin amounts varying between 10% and 200% by weight, on the charge, depending on the catalyst used. Due to these comparatively high amounts, where possible, recovery and regeneration of the catalysts have been proposed. 'Ihis, of course, involves high initial and operation costs. Further, it is also known that certain substances called promoters, promote the catalytic activity of these alkylation catalysts. Accordingly, several processes have been proposed wherein small amounts of these promoters, on the order ofabout 1% to 3% by weight on the charge, are added. to the. catalysts to promote their alkylation catalytic activity.

A copending application, Serial'Nurnber 502,018, filed September 11, 1943, is directed to theprocess of alkylating normal paraffinic or isoparaflinic hydrocarbons with olefinic hydrocarbons, which comprises contactinga normal paraffinic or isoparafiinic hydrocarbon and an olefinic hydrocarhot! in a reaction zone under alkylating condi- 3 tions, with small or promoter amounts of what has been termed therein, a homogeneous gaseous phase alkylation catalyst consisting essentially of a material that forms with the hydrocarbon reactants, a single homogeneous gaseous phase under the alkylation conditions of the reaction zone. The alkylation conditions of the process of this copending application, comprise a broad temperature range of about 590 F. to about 850 F., preferably, about 650 F. to about 825 F., and pressures of at least 500 pounds per square inch gauge, preferably, pressures of at least 1500 pounds per square inch.

Another copending application, Serial Number 502,813, filed September 17, 1943, is directed to the process of alkylating isobutane with pro pylene, which comprises contacting isobutane and propylene in a reaction 'zone under closely controlled alkylating conditions, with promoter or small amounts of the homogeneous gaseous phase catalysts broadly disclosed in the copending application referred to hereinbefore, the closely controlled alkylating conditions including a temperature range of about 750 F. to about 850 F., preferably, about 775 F. to about 825 F., and pressures of at least 2500 pounds per square inch gauge. In the alkylation of isobutane with propylene in the presence of homogeneous gaseous phase alkylation catalysts, it was found that the alkylate obtained included constituents that are entirely different from the constituents of the hydrocarbon alkylate obtained in the alkylation of isobutane with propylene in the presence of known heterogeneous alkylation catalysts, i. e., AlCls, H2SO4, and the like. Thus, when heterogeneous alkylation catalysts are used, 2,3-dimethylpentane and 2,4-dimethylpentane are important constituents of the hydrocarbon alkylate obtained. On the other hand, when homogeneous gaseous phase alkylation catalysts are employed, triptane or 2,2,3-trimethylbutane, 2,2- dimethylpentane, and Z-methylhexane may be the predominant constituents of the hydrocarbon alkylate. In this copending application, the formation of these three compounds was postulated as follows:

From a motor fuel standpoint, the 2,2-dimethylpentane produced by the first reaction, has an octane number of about 80 CFR. motor method; the triptane produced by the second reaction has an octane number of well over 100, and the 2-methylhexane obtained in the third reaction has an octane number of about 45. In view of the foregoing, in the manufacture of high-octane motor fuel by the alkylation of isobutane with propylene, alkylation conditions that favor the production of triptane obviously are preferable. Further, since neohexane which may be produced by the alkylation of isobutane with ethylene, has

. 'bons with olefinic hydrocarbons.

an octane number of 93.4, and since 2,3-dimethylpentane and 2,4-dimethylpentane which are the predominant constituents of the alkylate obtained in the alkylation of isobutane with propylene in the presence of heterogeneous alkylation catalysts, have octane numbers of 89 and 82, respectively, the importance of the alkylation of isobutane with propylene in the presence of homogeneous gaseous phase alkylation catalysts under alkylation conditions that favor the production of triptane is manifest. It was also found that in actual practice, it was impossible to obtain triptane exclusively, appreciable amounts of 2,2-dimethylpentane and 2-methylhexane being always formed.

The specific classes of homogeneous gaseous phase catalysts disclosed in these copending applications, are organic halogen compounds, and the claims are directed to the use of chlorine and bromine derivatives of acyclic hydrocarbons, as homogeneous gaseous phase alkylation catalysts. Chloroform, chlorinated naphtha, chlorinated butane, carbon tetrachloride, ethylene dibromide, acetyl chloride, propylene dibromide, dibromisobutane, ethyl bromide, propylene tribromide, and tertiary monobromo-butane are among the specific chlorine and bromine derivatives of acyclic hydrocarbons mentioned as suitable homogeneous gaseous phase alkylation catalysts for the alkylation processes disclosed in these copending applications.

The present invention is predicated On the use of organic halogen compounds, generally, as homogeneous gaseous phase alkylation catalysts, in the alkylation of paraffinic hydrocarbons with olefinic hydrocarbons, under the conditions set forth hereinbefore.

Accordingly, it is an object of the present invention to provide an eflicient process for alkylating isoparaffinic or normal parafiinic hydrocar- Another object is to provide an improved process for catalytically alkylating either normal parafllnic hydrocarbons or isoparaffinic hydrocarbons with olefinic hydrocarbons. A more specific object is to provide a process for catalytically alkylating normally gaseous isoparafiinic hydrocarbons with normally gaseous olefinic hydrocarbons, to produce high yields of high-octane gasoline. A Very important object is to afford a process for alkylating isobutane with propylene, to produce high yields of high-octane gasoline. A further object is to provide a process capable of carrying out the above objects by using small amounts of organic halogen compounds, as alkylation catalysts, that form, with the hydrocarbon reactants, a single, homogeneous gaseous phase during the alkylation operation. Other objects and advantages of the present invention will become apparent to those skilled in the art from the following description.

Broadly stated, our invention provides a process for alkylating normal parafiinic or isoparaflinic hydrocarbons, particularly isobutane, with olefinic hydrocarbons, particularly propylene and ethylene, which comprises contacting the paraffinic and olefinic hydrocarbons in gaseous phase and in a reaction zone under alkylating conditions, with small amounts of an alkylation catalyst consisting essentially of one or more organic halogen compounds, that forms with the hydrocarbon reactants, a single, homogeneous An important feature of the process of the present invention is the fact that, contrary to the .alkylating conditions.

o l ea 1 solids, liquids or ca es under n rm l. co dit n known catalytic. alkylationprocesses of the B 9 art which. are only capable of: alkylating isoparaflinic hydrocarbons, our pro e'ssis. cap l of; a1- y a e er normal paraffinic 0r isopara iinio hydrocarbons with substantially equal ease.

Another important feature is, the relatively low temperature that. may bev used; Asia result, degradation of the hydrocarbon reactants in the charge to. low molecular weight hydrocarbons and the pronounced occurrence of side, reactions, i cluding polymerization of the olefinic. hydrocar bons, are. substantially completely avoided. Consequently, in our process, we obtain high yields of a. high grade product. that, is. almost. entirely: par aifinic in nature and is substantially free from imp rities.

A very important feature of the. present invention is the fact that, contrary to known catalytic ,alkylation processes of the prior art in which the hydrocarbon reactants bein processed rm with the: allrylation catalysts, a heterogeneous system during the alkylation operation, the alkylation process of our invention, employs alkylation catalysts consisting essentially of materials that form with the hydrocarbon reactants being processed, a single homogeneous gaseous phase under The, alkylation catalysts of the present invention are called, therefore, and as noted hereinbefore; homogeneous gaseous phasealkylation catalysts, in contradistinction to the allsylation catalysts of the. priorart which are referred to as heterogeneous alkylation catalysts. Accordingly, as a. result of the catalysts being in the same phase or state as the hydrocarbon reactants being processed, fouling of the catalyst is substantially eliminated and agitation and/or mixing-problems are non-extant. Further, since the catalytic activity of alkylation catalysts appears to be predicated somewhat upon contact between the catalysts and the hydrocarbon reactants at the interfaces therebetween, it follows that the catalytic efficiency of a given catalyst increases with the increase in area of interfacial Contact, th ariables remainin con tant. Hence, since the homogeneous gaseous phase alkyla ion cat lysts of our pro es i herent y fu nish the greatest possible "inter-facial contact.

tw n t talyst and the. hydrocarbon reactants under the conditions of alkylation, efiiciont catalytic activitywith a concomitant high yield of high grade alkylate is achieved using relatively small amounts of homogeneous. gaseous phase. alkylation catalyst.

. n v of e fo e o ng a peration teatof h p ss o the pres nt. in e ti n hat; is o .=on ol b pr ical mp rtance, that mal o pr m te a ounts o or an c alo n oompoun sj e us d as alk lation cat ysts- Thes am unts re o s a l at hey ma be. d scarded, ea h eby ob iatin recover and gen a n pr b s and e iminat n hi h initia a pe ati n o "As di l sed in app ic tion Serial Numbe 502,018, filed September 11, 1943; and m application .Serial Number 502,813, filed September 17, 1943, a most important feature of homogeneous gaseous phase alkylation is that high yields .o high-o tane t r uel are b a ned by c r ins o th a kyla ion in he presen e of o rl h o e co poun s- As disclosed in application Serial Number 502,018, filed September 11, 1943, the. organic halogen compounds that are used as homogenephase allrylation catalysts, may be However, it is likewise e sent al. tor he Purposes or our pro es that the or an c halo n co pounds that; are. used s alkylation catal sts in t e proce s of the prese t: invention fo m. wi h the hydr ca bon reactant bein io oc e a single, homogeneous gaseous phase underthe alkylation conditions or the, reaction zone.- Aliphatic or acyclic. organic halo en compound such as methyl chloracet t chlora ao tyl r midc, ihr moe hyl o her, trifl oroac ti a d. isonropyl fluoride. ii o hyl. o e irsobutyl odide. o oiorm. dibromo-mo oi d m tha e. and the. likes. aloicyclic or anic. a en compounds, such as fiuocyclopropane, bromocyclo; butane and iodocyclobutane; and aromatic hale o en c mpounds. such as p-d hr rnoh nz ne. benzyl i dide and ben oyl; fluori e; have be n foun to be suitable. catal st or the p ocess of r invent on-v Gene a ly peak n th pre err d ca al s o our: inven on are the. halo en d rivatives of acyclic. a oyolic, and a omatic. by? drocarh ns, a i ularly t e ch ap. n readily a ailable lo -boi in hydrocar ns, rom, meth+ ans to hyd... ca bons. i h c bon atoms.

a halog n or hal e s, ha e b n s bs itu e for part or all th ydro n o a hyd ocar on r hydrocarbon. We es ecially prefer to use as. our ca y t halo en. derivatives of loweboi' in acy l c hydro a on and the tert ry halog n derivati es. of l w-boiling cycli hydroca b n ar am n h most desirable. the c lfioien y of ur a alyst ap a n yein som what in proportion. to he as w t wh ch hey dec mp se du ing the alkyla iq op rati ns I is. und s o d. o ours t at hydro en ha i es an elementa al gen re ctin h hy arb ns an be sed t orm t o gani hal n comp und ca aly ts-in i 'z he mo n of or anic ha ogen com o s used in, our process vary between. about 0.5% and about 3%, and preferably between about 1% 811 .9 about. 12.5%, with respect. to. the weight. of e otal charge of. hydrocarb n. r ac ants.- t must be noted, however, that. larger amounts may bev employed if desired, although no additional advantages seem. to result therefrom.

The parafiinic and olefinic hydrocarbons t be used in our process may be derived from any 50 suitable source, as is well known in the art, and

may beused either in the pure state or in admixe it oth r con ituents not un ir ble- Thg parafilnic and olefinic hydrocarbons usually em lo i he e e d op r n. o m f c- 55 tll irlg' motor fuels, will be. the normally gaseous paraffinic hydrocarbons, except methane and ethane, andthe, normally gaseous olefinic hydrocarbons, as is well understood in the art. 'Here again this proce s has a distinct advantage over 60 many of the prior art processes, in that the olefin ethylene may be used for alkylating the paraffinic hydrocarbons. It is well known that et ylene. cann t b us d n m n ly ic pr cesses, including the sulfuric acid process, where- 5by the supply of available olefinic hydrocarbons is restricted. Therefore, an important aspect of the present invention is the fact that butane, for may he aik lated with ethyl e- A conventional and preferred source of paraf- 7ofinic and olefinic hydrocarbons is the fixed gases obtained around petroleum refineries. These fixed gases may furnish substantially all the desired parafllnic and olefinic hydrocarbons, or it may be necessary or desirable to obtain addi- -t on l sup ies as is well unde stood... Additional 7 olefinic hydrocarbons, if required, may be formedfrom a portion of the parafiinic hydrocarbons. On the other hand, additional paraflinic hydrocarbons may be admixed to increase the concentration of paraffinic hydrocarbons to a desired tively low during the alkylation reaction, in order to eliminate as much olefin polymerization as possible. Accordingly, it is advisable to maintain the olefin concentration in the charge below Contact time in minutes.

about 25% by volume, and preferably between magnitude. about 7% and about 12% by volume. In con- In carrying out our process, we use temperatinuous operation, this is effected by introducing tures varying between about a bout the olefinic reactant at a number of points in the 850 F., and preferably temperatures varying bereaction zone or by adding the olefinic reactant to tween about 650 F. and about 825 F. In the a recirculating mass of excess paraflinic hydroalkylation of isobutane with propylene, however, carbon reactant, reaction product and catalyst. it was found, as disclosed in copendingappli ca- The reaction period during which the reacttion Serial Number 502,813, filed September 17, ants are present in the reaction zone depends 1943, that the best yields of desired alkylate are upon the temperature, and to a certain extent, obtained when the alkylation is conducted at 15 upon the pressure. Ordinarily, a reaction period temperatures falling within about 750 F. to about varying between 1 to 2 minutes and 1 to 2 hours 850 F., and preferably, about 775 F. to about is satisfactory. 825 F. The alkylate produced under these con- It must be understood, that the reaction variditions contains no more than 5% of olefinic hyables are more or less interdependent, hence, drocarbons and n0 aromatics so that the prewhen on isarbitrarily fixed, the limits within dominance of alkylation obtained thereby is a which the others may be varied, are somewhat distinct feature of the process. Under apprecirestricted. In any particular instance, the most ably higher temperature conditions, secondary redesirable conditions can be readily ascertained actions occur that substantially reduce the purity by one skilled in the art, the preferred ranges ofv of the product obtained, as noted hereinbefore these variables having been indicated hereinbein connection with thermal alkylation. In the fore.

, alkylation of isobutane with propylene in ac- The alkylate product that we obtain distills cordance with the process of the present invenover a fairly large boiling range, but a greater tion, it must be noted that even within the prepart of the alkylate, usually from about 85% to ferred temperature range, side reactions occur about 90%, distills in the boiling range of aviathat account for substantial portions of the total tion gasolines. The iodine number of the aviaalkylate, but a fraction boiling at 79 C. to 82 C. tion distillate is low, on the order of about 5 to and consisting of 15 parts of triptane to 85 parts 10. As mentioned hereinbefore, the alkylate of 2,2-dimethylpentane may be obtained. product consists predominantly of branched par- Th pressure to be used in our process may afiinic hydrocarbons. vary from about 500 pounds per square inch to Numerous experimental data could be adduced about 6000 pounds per square inch or more, and to indicate the results obtainable by employing preferably from about 2500 pounds per square the homogeneous gaseous phase catalysts of the inch to about 6000 pounds per square inch for present invention, but the following examples the alkylation of isobutane with propylene, the 40 are sufiiciently characteristic:

, Run 1 Run 2 Run3 Run 4 Per cent by weight of isobutane in charge 92.82 88.9. Per cent by weight of propylene in charge l0 9.9. Per cent by weight of ethylene in harge 5.6

Catalyst V p-Dibromobenzene Isopropylfiuoride; Per cent of catalyst by wcig 1.58 1.2. 1

Residence time in minutes. Temperature, F

Pressure, lbs/sq. in. gauge Per cent yield of alkylate based on weight of olefine. Per cent yield of alkylate based on weight of charge Per cent triptane in 7686 0. fraction of a1kylate Per cent neoliexane fraction (44-54 C.) in alkylate.

most suitable pressure being more or less de pendent upon the particular temperature in volved. In general, the higher the pressure, the higher the yield of alkylate. Accordingly, the criterion for establishing an upper limit to the -pressure range used is primarily the feasibility of maintaining such pressure.

geneous gaseous phase catalysts of our invention. This may be effected in several ways, asis well known in the art. 1

In our process it is desirable, as in known isoparafiin-olefin alkylation processes, to'keep the concentration of the olefinic hydrocarbons rela-" This application is a continuation-in-part of our copending application Serial Number 502,018,

filed September 11, 1943.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it 'is therefore desired that the present embodiments be considered in all respects as illustrative and not restrictive, reference being had to the appended claims rather than to the foregoing description to indicate the scope of the invention.

9 We claim: 1. The process of manufacturing triptane,

which comprises contacting isobutane and propylene in gaseous phase in a reaction zone under alkylating conditions including a temperature varying between about 775 F. and about 825 F.

and a pressure in excess of 2500 pounds per square inch, with an alkylation catalyst consisting essentially of material selected from the group consisting of acylic organic halogen compounds, alicyclic organic halogen compounds, and aromatic organic halogen compounds, that forms with said isobutane and said propylene, a single, homogeneous gaseous phase under said alkylating conditions, in amounts of at least about 0.5% by weight based on the total weight of said isobutane and said propylene, and maintaining said isobutane in excess over said propylene in said reaction zone so that alkylation is the principal reaction.

2. The process of claim 1 wherein the alkylation catalyst consists essentially of a halogen derivative of a hydrocarbon.

3. The process of claim 1 wherein the alkylation catalyst consists essentially of a halogen derivative of a low-boiling hydrocarbon.

4. The process of claim 1 wherein the alkylation catalyst consists essentially of a fluorine derivative of a low-boiling acylic hydrocarbon.

5. The process of claim 1 wherein the alkylation catalyst consists essentially of an iodine derivative of a low-boiling acylic hydrocarbon.

6. The process of manufacturing high-octane gasoline, which comprises contacting isobutane and propylene in gaseous phase in a reaction zone under alkylating conditions including a temperature varying between about 750 F. and about 850 F. and a pressure in excess of 2500 pounds per square inch, with an alkylation catalyst consisting essentially of material selected from the group consisting of acyclic organic halogen compounds, alicyclic organic halogen compounds, and aromatic organic halogen compounds, that forms with said isobutane and said propylene, a single, homogeneous gaseous phase under said alkylating conditions, and maintaining said isobutane in excess over said propylene in said reaction zone so that alkylation is the principal reaction.

7. The process of claim 6 wherein the alkylation catalyst consists essentially of a halogen derivative of a hydrocarbon.

8. The process of claim 6 wherein the alkylation catalyst consists essentially of a halogen derivative of a low-boiling hydrocarbon.

9. The process of claim 6 wherein the alkylation catalyst consists essentially of a fluorine derivative of a low-boiling acyclic hydrocarbon.

10. The process of claim 6 wherein the alkylation catalyst consists essentially of an iodine derivative of a low-boiling acyclic hydrocarbon.

11. The process of manufacturing high-octane gasoline, which comprises contacting a normally gaseous paraifinic hydrocarbon and a normally gaseous olefinic hydrocarbon in gaseous phase in a reaction zone under alkylating conditions inly gaseous olefinic hydrocarbon, a single, homogeneous gaseous phase under said alkylating conditions, in amounts of at least about 0.5% by weight based on the total weight of said normally gaseous parafiinic hydrocarbon and said normally gaseous olefinic hydrocarbon, and maintaining said normally gaseous paraflinic hydrocarbon in excess over said normally gaseous olefinic hydrocarbon in said reaction zone so that alkylation is the principal reaction.

12. The process of claim 11 wherein the alkylation catalyst consists essentially of a halogen derivative of a hydrocarbon.

13. The process of claim 11 wherein the alkylation catalyst consists essentially of a halogen derivative of a low-boiling hydrocarbon.

14. The process of claim 11 wherein the alkylation catalyst consists essentially of a fluorine derivative of a low-boiling acyclic hydrocarbon.

15. The process of claim 11 wherein the alkylation catalyst consists essentially of an iodine derivative of a low-boiling acyclic hydrocarbon.

16. In a process of alkylating a paraffinic hydrocarbon with anolefinic hydrocarbon, which includes reacting a parafilnic hydrocarbon with an olefinic hydrocarbon in a reaction zone under alkylating conditions, in the presence of an alkylation catalyst; the improvement which comprises contacting said paraflinic hydrocarbon and said olefinic hydrocarbon in gaseous phase in a reaction zone under alkylating conditions including a temperature varying between about 590 F. and about 850 F. and a pressure in excess of 500 pounds per square inch, with an alkylation catalyst consisting essentially of material selected from the group consisting of acyclic or ganic halogen compounds, alicyclic organic halogen compounds, and aromatic organic halogen compounds, that forms with said paraffinic hydrocarbon and said olefinic hydrocarbon, a single, homogeneous gaseous phase under said alkylating conditions, and maintaining said paraifinic hydrocarbon in excess over said olefinic hydrocarbon in said reaction zone so that alkylation is the principal reaction.

17. The process of claim 16 wherein the alkylation catalyst consists essentially of a halogen derivative of a hydrocarbon.

18. The process of claim 16 wherein the alkylation catalyst consists essentially of a halo-gen derivative of a low-boiling hydrocarbon.

19. In the process of alkylating a parafiinic hydrocarbon with an olefinic hydrocarbon, which includes reacting a parafiinic hydrocarbon with an olefinic hydrocarbon in a reaction zone under alkylating conditions, in the presence of an alkylation catalyst; the improvement which comprises contacting said paraffinic hydrocarbon and said olefinic hydrocarbon in gaseous phase in a reaction zone under alkylating conditions, with an alkylation catalyst consisting essentially of a fluorine derivative of a low-boiling acyclic hydrocarbon, that forms with said parafiinic hydrocarbonand said olefinic hydrocarbon, a single, homogeneous gaseous phase under said alkylating conditions, and maintaining said paraifinic hydrocarbon in excess over said olefinic hydrocarbon in said reaction zone so that alkylation is the principal reaction.

20. The process of claim 19 wherein the alkylation catalyst consists essentially of an iodine derivative of a low-boiling acyclic hydrocarbon.

ALEXANDER N. SACHANEN. ARLIE A. OKELLY. CLAUDE G. MYERS. 

